敷设声学覆盖层结构在水下爆炸作用下的流固耦合分析

为解决水下冲击波作用下带声学覆盖层结构的动响应问题，提出了敷设声学覆盖层结构遇水下非接触爆炸冲击波的流固耦合分析方法.冲击早期高频作用段采用声学波动理论，以冲击波在水、覆盖层、钢板中的传播过程为研究对象，利用冲量等效修正冲击早期Taylor板模型反射系数；冲击波早期高频段过后，覆盖层的影响主要体现在其质量效应上，将覆盖层质量加载在其对应的结构有限元结点上，并结合二阶DAA，给出流固耦合计算方法，分析结构动响应，该方法大大缩减了有限元计算规模.最后实施了敷设去耦瓦加筋圆柱壳水下爆炸试验，其加速度峰值与试验偏差在20%以内，速度峰值偏差在10%以内，应变峰值偏差在15%以内，充分验证了计算方法.

Fluid-Structure Interaction on a Plate Subjected to Underwater Explosion with Acoustic Tiles

In order to get the dynamic response of the structure with acousitic tiles subjected to underwater explosion, the analytical method of fluid-structure interaction has been developed. Acoustic wave equation was adopted in the early of shock time at which the force is of very high frequency. By taking the propagation process of shock wave in the water, anechoic coating and steel layer as the research object. Impulse equivalency was used to modify the reflection coefficient of the shock wave in the Taylor''s plate model. Next the effect of anechoic coating is mainly due to its mass, so the mass of coating was added on the corresponding nodes of finite model. Then combined with the DAA2 method, the computation method of fluid-structure interaction for the dynamic response was presented to analyze the dynamic response. The method decreases calculation scale greatly. Finally, tests of underwater explosion were carried out on stringer-stiffened cylinder covered with anechoic coating. The relative errors of accerleration amplitude, velocity amplitude and strain peak value are in 20%,10% and 15% compared to the test result, which verified the reliability of the calculation method.